An efficient synthesis of anti-microbial 1,2,4-triazole-3-thiones promoted by acidic ionic liquid

Synthesis and Antimicrobial Activity of Novel Hydrazone and 1,2,4-Triazole-3-thione Derivatives

Abstract

Novel hydrazone and 1,2,4-triazole-3-thione derivatives were obtained via the reaction of N1,N3,2-triaryl-6-hydroxy-6-methyl-4-oxocyclohexane-1,3-dicarboxamides with acid hydrazides and thiosemicarbazide, respectively. Structure of the products was proved using IR and 1H NMR spectroscopy methods. Some of the synthesized compounds were tested for antimicrobial activity

L-Proline nitrate: An Efficient Amino Acid Ionic Liquid Catalyzed Synthesis of 5-aryl-[1, 2, 4]-triazolidine-3-thiones

Abstract:

An environmentally benign, simple, rapid synthesis of 1,2,4-triazolidine-3-thiones at room temperature is reported using amino acid-derived Brønsted acidic ionic liquid L-proline nitrate [Pro+NO3-] from aldehyde and thiosemicarbazide in an aqueous medium. A cost-effective and energy-efficient catalyst with the reusability of up to five cycles without significant loss in the catalytic activity makes this protocol superior. A faster reaction, easy work-up with excellent yields are the added advantages of this protocol.

Green and efficient synthesis of 1, 2, 4-Triazolidine-3-thiones using guanidine hydrochloride as a recyclable catalyst under the aqueous condition

Abstract:

A rapid and highly efficient methodology for the synthesis of 1, 2, 4-Triazolidine-3-thiones derivatives has been developed in the presence of a catalytic amount of guanidine hydrochloride using water as a solvent. The reaction of thiosemicarbazide with different aryl aldehydes resulted in the formation of title compounds in good yields (85% -95%) with a convenient reaction time (20-30 min). The key advantages of this approach are shorter reaction time, energy efficiency, easy work-up procedure, and wide substrate scope tolerance. Further, the catalyst was recycled without significant loss of its catalytic activity

Synthesis of New Planar-Chiral Linked [2.2]Paracyclophanes-N-([2.2]-Paracyclophanylcarbamoyl)-4-([2.2]Paracyclophanylcarboxamide, [2.2]Paracyclophanyl-Substituted Triazolthiones and -Substituted Oxadiazoles

The manuscript describes the synthesis of new racemic and chiral linked paracyclophane assigned as N-5-(1,4(1,4)-dibenzenacyclohexaphane-1²-yl)carbamoyl)-5’-(1,4(1,4)-dibenzenacyclohexaphane-1²-yl)carboxamide. The procedure depends upon the reaction of 5-(1,4(1,4)-dibenzenacyclohexaphane-1²-yl)hydrazide with 5-(1,4(1,4)-dibenzenacyclohexaphane-1²-yl)isocyanate. To prepare the homochiral linked paracyclophane of a compound, the enantioselectivity of 5-(1,4(1,4)-dibenzenacyclohexaphane-1²-yl)carbaldehyde (enantiomeric purity 60% ee), was oxidized to the corresponding acid, which on chlorination, gave the corresponding acid chloride of [2.2]paracyclophane. Following up on the same procedure applied for the preparation of racemic-carbamoyl and purified by HPLC purification, we succeeded to obtain the target Sp-Sp-N-5-(1,4(1,4)-dibenzenacyclohexaphane-1²-yl)carbamoyl)-5’-(1,4(1,4)-dibenzenacyclohexaphane-1²-yl)carboxamide. Subjecting N-5-(1,4(1,4)-dibenzenacyclohexaphane-1²-yl)hydrazide to various isothiocyanates, the corresponding paracyclophanyl-acylthiosemicarbazides were obtained. The latter compounds were then cyclized to a new series of 5-(1,4(1,4)-dibenzenacyclohexaphane-1²-yl)-2,4-dihydro-3H-1,2,4-triazol-3-thiones. 5-(1,4(1,4)-Dibenzenacyclohexaphane-1²-yl)-1,3,4-oxadiazol-2-amines were also synthesized in good yields via internal cyclization of the same paracyclophanyl-acylthiosemicarbazides. NMR, IR, and mass spectra (HRMS) were used to elucidate the structure of the obtained products. The X-ray structure analysis was also used as an unambiguous tool to elucidate the structure of the products.

Hassan A, Makhlouf MM, Bräse S. Chemistry and Biological Activities of 1,2,4-Triazolethiones-Antiviral and Anti-Infective Drugs

Mercapto-substituted 1,2,4-triazoles are very interesting compounds as they play an important role in chemopreventive and chemotherapeutic effects on cancer. In recent decades, literature has been enriched with sulfur- and nitrogen-containing heterocycles which are used as a basic nucleus of different heterocyclic compounds with various biological applications in medicine and also occupy a huge part of natural products. Therefore, we shed, herein, more light on the synthesis of this interesting class and its application as a biologically active moiety. They might also be suitable as antiviral and anti-infective drugs.

Functionalized 1,3-Thiazolidin-4-Ones from 2-Oxo-Acenaphthoquinylidene- and [2.2]Paracyclophanylidene-Thiosemicarbazones

The reactions of dialkyl acetylenedicarboxylates with various 2-oxo-acenaphthoquinylidene- and 4-acetyl[2.2]paracyclophanylidene-thiosemicarbazones were investigated. Using simple experimental procedures, 1,3-Thiazolidin-4-ones derived from acenaphthequinone or [2.2]paracyclophane were obtained as major products in good yields. In the case of allyl derivative of acenaphthoquinylidene-thiosemicarbazones, a complex structure of tetramethyl 5-(2-(((Z,E)-N-allyl-N′-(2-oxoacenaphthylen-1(2H)-ylidene)carbamohydrazonoyl)thio)-1,2,3-tris-(methoxycarbonyl)-cyclopropyl)-4-methoxy-7-oxabicyclo[2.2.1]hepta-2,5-diene-1,2,3,6-tetracarboxylate was formed. Single crystal X-ray analysis was used as an efficient tool to confirm the structure of the synthesized compounds as well as different spectroscopic data (¹H-NMR, ¹³C-NMR, 2D-NMR, mass spectrometry and elemental analysis). The mechanism of the obtained products was discussed.

Efficient synthesis of novel pyrazole-linked 1,2,4-triazolidine-3-thiones using bismuth on zirconium oxide as a recyclable catalyst in aqueous medium

The Bi₂O₃ loading on ZrO₂ as heterogeneous catalyst was established as an extremely efficient catalyst for the synthesis of a series of novel 5-(1-(2,4-dinitrophenyl)-3-substituted-phenyl-1H-pyrazol-4-yl)-1,2,4-triazolidine-3-thione derivatives (3a-o) with high yields (90-96%) by reaction of 1-(2,4-dinitrophenyl)-3-substituted-phenyl-1H-pyrazole-4-carbaldehydes and thiosemicarbazide using water as a greener solvent at 80 °C within 30-45 min. Materials with different percentages of Bi₂O₃ on ZrO₂ were prepared by simple wet impregnation method. The synthesized material has been characterized by various techniques (XRD, TEM, SEM, BET). 2.5% Bi₂O₃/ZrO₂ proved superior catalyst. The Bi₂O₃/ZrO₂ catalyst is easily recoverable and reused up to sixth run with no loss of activity. Excellent yields, short reaction time, avoidance of hazardous solvents, and no need for chromatographic purifications are the proven advantages.